In an existing wireless communications system, a mobile terminal accesses a network using a wireless access device. The mobile terminal is movable. Quality of a wireless access link between the mobile terminal and the wireless access device may vary when the mobile terminal moves to different locations. For example, the quality of the wireless access link deteriorates when the mobile terminal is located relatively far away from the wireless access device. An existing wireless access device is generally disposed at a specific location fixedly, and therefore, a communication quality requirement of the mobile terminal cannot be satisfied when the mobile terminal is far away from the wireless access device for reasons such as movement.